Apparatus for trapping dust arising in bore holes



J. N. HUNTER Feb. 8, 1938.

APPARATUS FOR TRAPPING DUST ARISING IN BORE HOLES Filed Jan. 8, 1936 INVENTOR. /fL /M f Y al 41M.; l Mr ATTORNEY .5

f Patched Feb. a,y 193781 'Jol-nrV Norman Hunter, Norbury, England, asv signor to Pyrenev Manufacturingy Company,

ginestra e Newark, N.' J., a corporation olf-Delaware C f 'Irhisfinventionrelatesto that kind of apparatus .Y y figortrappingvdust arising' in boreholes in which Y ,suction'is applied-to ar conduit through'which,

a Y ff du-stfladen air is drawn away from'the'mouth of f the hole,l usually to some form of iilter.`

d lf'According to the inventiony a suction tube arranged to surround adrill shank is formed with a mouth which is adapted to enter the mouth of as bofrehole vand which is preferably tapered for` vlQQthis purposagand is also formed with a connection f through which Vsuction may be applied. 'I'huswhen the end of the suction tube-.has been -:jflodged'in the bore holethe tube serves not-only. 'asa receiver'for. the dust but also-asa guide fory l5,` thedrillshank. 4' The tube is4 preferably'made of y, i

'springksteel or equivalent resilient4 material and isgsiotteqf pr 'Surat 'the mouth end-so .thatV the f.; 1,atterf,.canj bear tightly against the wall of the In .'ordertorcatch anyv dust that arises ywhen ffdrilling starts, a hood maybe mounted on the suction tube and arranged to surround the end of, thefdrill when adrilling operation is being begun, that isto say before a hole of sufficient depth tube. f Y n Y 1 f f In order thatthe'invention may be'clearlyunv has been madelto receive the mouth of the suctionV `-derstood and readilycarried into effect two appa-Y -fratusf constructed in accordance therewith .will

30 now ybei described byl Way of example ywith refer-` y '1 enceto the accompanying drawing,A in which the twojigures respectively ,show these apparatus partlyin section.

' Fig. 1 is an elevational view, partly, in section, ofioneiembodiment of myV invention `and Fig. 2

Q isasimilar'view of amodified form.

'tion, lthe mouth of which is narrower than the bit 45of.,thevdrill.` The tapered'portion is formed 1` lffwithfa siotjs which runsiinelically. around it. A branchisconnected by a flexible pipe 1 to an jhoodiis pushed forward so thatjits edge bears on Figfl.

VKReferring first tojFig..l, a suction tubelfis arrangedaround thejrshankrof a drill, and `at- .thefmouthljend isrformedwith a tapering por- Y.

n Application january, V` 1936, Serial No. 58,043k Y. In GreatBritainFebruaryS, 1935 l 'Y i z claims. (o1. e-5o) l v VV'hood andthrough Ythe slot 5, even if the hood is in 'the position shown in Fig. 1. In practice the operator supports the end of the drill shank by holding the suction' tube Iin one hand, and as drilling proceeds the tube enters the hole.

soon as the hole'has been made suiiiciently deep to support the end of the suction tube there is no longer-any need for the operator to hold this tube. vAs is clearly shown by Fig. 1, the suction tube is made of such diameter that the drill shank can 10 Y revolve freely'and does not obstruct the free flow of dust upv the tube and through the branch 6.

In the construction shown in Fig. 2, the mouth end 3of,the tube is formed with straight longitudinal slits 9 and is surrounded by a hood I0 oi- 15 a slightly diierent design from that shown in y l In this .casethe flexible conical part of the hoodis carried bya stiff` annular member i4 ywhich may be arranged to slide on the tube I.

yI1 thev suction exerted through the branch 6 is 20 yinsuilicient to insure that all the dust is drawn throughlthe branch 6, the end of the tube may be Y positivelysealed, as shown in Fig. 2, to prevent anyair escaping between thetube and the drill shank 2. This sealing is effected by an annular 25 rubber disc I I which fits around Vthe drill shank 2 and is covered by ametal ring |12 at its rim. This riml2 lies in a groove formed ina casting I 3 fixed to the'end ofthey tube land floats'in this grooveso that the Wholeseal alsoconstitutes a bearing vfor the drill shank 2.

Itrwill be understood that the invention may assumekforms other than those herein shown and described without departing from the spirit of What is claimed is: '1.'An apparatus for trapping dust arising in `bore holes, comprising a tube of resilient metal kadapted to surround a drill `shank andprovided with a connection through which suction may be 40 induced,` the wall of said tubebeing gradually tapered throughoutA a substantial portion of its rlength to facilitate its partial entrance into a bore hole/and yslotted also throughout a substantial fpo'rtionof its Vlength'to render it readily con- 45 f tractible. yunder .the impinging action exerted :fthereonby the Wall o f the bore hole as it enters Athe same, the slotted area of said wall being suff inciently. long to serve as a passage through which airis `drawn into the tube from the Yvicinity of "the outer end'of the bore hole under the action VK the-rock facefand surrounds" the areaV uponvwhich f the,dri1l acts. However.iiconsiderableY suction n Y Jisfapplid'through the branchl pipe Alitfisvrfoundv' "Q thatfthe clusty initially formed is zdrawninto the'v 2. `Anxapparatus for trapping dust arising in 55 impinging action exerted thereon by the wall of g the bore hole as it enters the same, the slotted area of said Wall extending along a helical path and serving as av passage through which air is drawn into the tube from the Vicinity of the outer end of the bore hole under the action of induced suction Within the tube during such time as the tapered end of the tube is disposedv Within the bore hole.

JOHN NORMAN HUNTER. 

